As is well known in the art, environmental requirements, over the past decade or two, have made it essential that vapors and fumes generated during fuel dispensing, particularly at the myriad of service stations, be collected, at a high degree of efficiency, to prevent the entrance of such fumes into the atmosphere. Environmentalists have stated that these types of fumes may be detrimental to the quality of our air.
As a result, many different types of devices have been constructed, formulated, and which function essentially to recover a large part of the gasoline vapors, from the interface between the service station dispenser, the nozzle, and where it inserts into the automobile fill tank, in an effort to collect the generated vapors, and return or pump them back into the underground storage facility, in an effort to reduce such pollutants.
These types of vapor recovery systems may include pumps within the dispenser, that suck the vapors from the region of the nozzle, or from the vehicle fill tank, and return them back to storage, or in some instances, the low pressure generated proximate the venturi of a gasoline dispensing nozzle, may utilize its suction force to manipulate such vapors, for the purpose of their immediate collection. But, when these types of techniques are used to recover vapors, due to the condensability of such fuels, there is always the likelihood that the vapors may contain a certain amount of the fuel moisture, which may condense or coagulate into droplets, and accumulate in the dispensing hose, rather than get returned back to the dispenser, and to underground storage, as desired. As a result, it is necessary to keep these accumulated pockets of liquid fuel from blocking the vapor return pass within the coaxial fuel hose, which would otherwise prevent the return of vapors, and block their transmission back into storage. When that occurs, the vapors overflow from the nozzle, or from the vehicle, the return suction is eliminated, meaning that such vapors are disseminated into atmosphere, not only to present the alleged detriments claimed by the environmentalists, but also probably in violation of the various laws that have now been promulgated to require the collection of such vapors.
Hence, devices have been constructed which provide for the elimination of such accumulated fuels, particularly in the vapor return portion of the coaxial fuel dispensing hose, to eliminate this predicament. Such devices normally are called slurpies, as known in the art. The slurpie utilizes a small tube, that rests at the bottom of the low point of the fuel dispensing hose, in the vapor recovery line, interconnects from the hose through the nozzle and is subject to the vacuums generated by the venturi contained within the dispensing nozzle, to draw such accumulated droplets or pockets of fuel, back into the nozzle, and entrain them into the flow path of the fuel being dispensed by the nozzle into the fill tank of the vehicle. This has worked quite effective, in the past, to keep such vapor return lines clear, and unobstructed.
Examples of various types of vapor recovery systems, some of which may disclose slurpies, are shown in various prior United States patents. For example, U.S. Pat. No. 5,520,228, discloses a fuel extraction coupling for a nozzle. This shows the coupling for the tubing that connects with the slurpie pick up point, to deliver or provide for an extraction of any pooled fuel from the vapor recovery hose. U.S. Pat. No. 5,476,125, discloses a vapor recovery gasoline dispensing nozzle. In addition, a vapor control valve, for use in a fuel dispensing nozzle, is shown in U.S. Pat. No. 5,394,909. Also, U.S. Pat. No. 5,197,523, shows a dispensing nozzle improvement for extracting fuel from the coaxial hose, in the manner as previously described. All of these prior patents, as described herein, are owned by a common assignee to the invention as reviewed and explained in this application.
Other patents that show related technology include a coaxial hose assembly, as disclosed in U.S. Pat. No. 5,285,744. U.S. Pat. No. 4,566,504, shows an insertion tube liquid evacuator system for vapor recovery hose, of an early embodiment. U.S. Pat. No. 4,687,033, shows another early venturi liquid evacuator system for maintaining a clear vapor path in vapor recovery hose. These are examples of what are known in the prior art.